1. Field of the Invention
The present invention relates to a plane printing machine to print on the surface of an object, more specifically to a printing machine applicable for plane printing on the surface of a prismatic body like a square bottle.
2. Description of the Prior Art
A device for printing on the side surface of a prismatic body like a square bottle has been available for a long time and there are a wide variety of them. The typical machine employed in the bottle-making industry for printing on square bottles is of such a system that many spindles are fitted to a pair of parallel-moving endless chains; a square bottle is chucked to each spindle; at the printing station the spindle is pushed up to bring the bottle close to the plane printing screen; and the printing is done on the surface of the bottle by the screen pressed against it by a squeegee. The printing machine of this system has the merits that a large number of printing stations can be easily set up and multicolor printing is easy to execute; but the demerits that it takes long time to exchange the parts with another ones for other type of bottles; routine maintenance of the machine is troublesome; the accuracy of printing is low; and, being a chain conveyor system, the machine is unfit for high-speed operation. Therefore such a printing machine is not necessarily satisfactory.
There is also a semi-automatic printing machine in which the feed and delivery of bottles are done manually, but, as a matter of course, this one is not available for high-speed operation either.
Thus no printing machine has existed which can execute fast, exact printing on the surface of such an object as square bottle with use of a few spindles.